Fig. 4

Surface energy and stress of nanoparticles (upper rows) and cavities (lower rows) as a function of applied pressure, for aluminum (left column), silicon (middle column) and iron (right column). Each curve corresponds to a nanoparticle/cavity diameter value, in a 2 nm to 20 nm range. Two different 2 nm Si nanoparticles have been investigated, which explains the presence of two violet curves in the corresponding graphs